JPS62234862A - Fluorescent lamp - Google Patents

Abstract

PURPOSE:To improve color rendering together with not only color difference but also output property, by specifying respective ratios of mixture consisting of blue/green phosphor and dark red phosphor as well as forming a non- luminous layer between a glass bulb and a luminous layer. CONSTITUTION:The respective ratios of blue/green phosphor and dark red phosphor occupying the mixture thereof are set in a range from 5 weight% to 30 weight%. When the mixed amount of blue/green phosphor is reduced below 5 weight%, the average color rendering evaluation number Ra can not be improved and when it exceeds 30 weight% on the contrary, special color rendering evaluation number R9 is decreased. Further, when the mixed amount of dark red phosphor is reduced below 5 weight%, Rg can not be improved and when it exceeds 30 weight% on the contrary, the optical output property is decreased by approximately more than 10%. Thus, both the abovementioned phosphor are mixed together by respective adeguate quantities so that Ra and R9 can be improved effectively. In addition, since a non-luminous layer having action of absorbing ultra-violet ray is formed between a glass bulb and a luminous layer, not only color difference but also the optical output property can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fluorescent lamp, and more particularly to a fluorescent lamp with good light output characteristics and color rendering properties suitable for display lighting for foods and the like.

Conventional technology Generally, display lighting for fresh fish, shellfish, meat, and vegetables uses D-8DL, W-8DL, which has an SDL color rendering class, or antimony-activated calcium helophosphate fluorescent light that emits blue-white light on the inner surface of a glass bulb. body, antimony- and manganese-activated strontium halophosphate phosphor with edge-colored luminescence, tin-activated strontium/magnesium phosphate phosphor with light red luminescence, europium-activated yttrium oxide phosphor with red luminescence, red luminescence A fluorescent lamp is used, which is constructed by coating a mixed member consisting of a europium-activated yttrium phosphovanadate phosphor and a manganese-activated magnesium fluorogermanate phosphor that emits deep red light.

This fluorescent lamp has a good average color rendering index or special color rendering index, and can make the colors of fish, shellfish, meat, and vegetables look good. It is considerably worse at about 70% compared to optical lamps.

In recent years, three-wavelength fluorescent lamps with good light output characteristics and high color rendering properties have come to be used for lighting, but their special color rendering index is low at lO~20, making them difficult to use for fish, shellfish, meat, etc. Not suitable for display lighting of vegetables.

Problems to be Solved by the Invention For this reason, the applicant has previously developed
Rare earth phosphor with nearby emission peak and 660nrr
We prototyped a fluorescent lamp in which a light-emitting layer was formed by coating the inner surface of a glass bulb with a mixed material containing a deep red phosphor with an emission peak, and examined its color rendering properties, light output characteristics, and economic efficiency. As a result, it was confirmed that the desired objectives were achieved with respect to the light output characteristics and the special color rendering index R9.

However, regarding color rendering properties, the average color rendering index ≦△ was 80, which did not satisfy the minimum value of 85 for W-8DL specified in JIS Z9301. Also, there is a color difference between both ends of the fluorescent lamp, and when compared at 40 watts, F
While the color difference ΔE of L408EX is 0.7 x 10-3, the color difference ΔB of the prototype fluorescent lamp is 4.3 x 10-3.
Very great results were obtained. Furthermore, a problem arose in that the phosphor mixture member was expensive at 50,000 to 60,000 yen/kg.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an inexpensive ultraviolet-cut type fluorescent lamp that can improve color rendering properties and reduce color difference without impairing light output characteristics.

Means for Solving the Problems Therefore, in order to achieve the above-mentioned object, the present invention has a light-emitting layer formed on the inner surface of a glass bulb, in which a light-transmitting and ultraviolet-absorbing layer is provided between the glass bulb and the light-emitting layer. A non-emissive layer having a function is formed, and the emissive layer is composed of a mixed material of a narrow-band emitting phosphor, a blue-green phosphor and a deep red phosphor that are excited even in the back-color region, and The proportion of the blue-green phosphor and the deep red phosphor in the mixed member is 5 each.
~30 layers (as set).

However, when the amount of the blue-green phosphor mixed is less than 5% by weight, the average color rendering index Ra is not improved, and the reverse 1c3
If it exceeds 0% by weight, the texture will decrease.

Furthermore, if the amount of the deep red phosphor mixed is less than 5% by weight, no improvement will be achieved, and if it exceeds 30% by weight, the light output characteristics will decrease by 10 inches or more. Therefore, it is not preferable to deviate from this range.

According to the present invention, since appropriate amounts of a blue-green phosphor and a deep red phosphor are mixed with the rare earth phosphor constituting the light-emitting layer, the average color rendering index Ra and the special color rendering index can be effectively improved. It can be improved.

In addition, since a non-emissive layer that has an ultraviolet absorbing effect is formed between the glass bulb and the emissive layer, not only the color difference but also the
Light output characteristics can be significantly improved, and ultraviolet rays can also be effectively blocked.

Furthermore, since the luminous efficiency is increased by the presence of the non-luminescent layer that reflects ultraviolet rays, the coating weight of the luminescent layer can be reduced by the increased efficiency, and the cost of the fluorescent lamp can be effectively reduced.

Example Next, specific examples of the present invention will be described.

The phosphors shown in Table 1 were mixed as shown in Table 2, placed in a pot with 3% ethylcellulose, Kijilor iWi, and 7/9 mina (At2o3), and ball milled for 1 hour to make a suspension. , titanium oxide (Ti) on the inner surface.

A 40 W fluorescent lamp was manufactured by coating a glass bulb with and without a non-emissive layer having an ultraviolet absorbing effect, respectively.

When these fluorescent lamps were photometered and the light source color was measured, the chromaticity, color rendering plan number, color difference, and luminous flux shown in Tables 3 and 4 were obtained.

Table-1 Table-2 Table-3 As is clear from Tables-3 and 4, the color difference between both ends of the fluorescent lamp and the light output characteristics (total luminous flux, luminous flux maintenance rate) are significantly improved by forming the non-luminous layer. Not only that, but the color rendering index can also be improved. Moreover, the coating weight can be reduced by 30%, and the cost can also be effectively reduced.

Next, mix 1 of blue-green phosphor and deep red phosphor in Table-5.
When the changes were made as shown in the table, the results shown in the table were obtained. Incidentally, all of the fluorescent lamps No. 2 to No. 13 in the table have a non-emissive layer formed of titanium oxide.

Table 5 As is clear from Table 5, the proportion of blue-green phosphor and deep red phosphor in the total phosphor is 5 to 30% by weight, respectively.
By setting the color rendering index to , the color rendering index can be effectively improved.

In the present invention, the blue-green phosphor and the deep red phosphor are not limited to the phosphors shown in Table 1, and can be changed as appropriate. Furthermore, the non-emissive layer may be made of a material other than titanium oxide, such as magnesium oxide or aluminum oxide.

Effects of the Invention As described above, according to the present invention, a non-luminous layer having an ultraviolet absorbing effect is formed between the glass bulb and the luminescent layer, so even if the light is turned on for a long time, there is no discoloration to light gray. Not only can it be completely eliminated, but also the color difference and light output characteristics can be significantly improved. Furthermore, in connection with the formation of the non-emissive layer, the coating weight of the emissive layer can be reduced, and lamp costs can be effectively reduced.

Furthermore, by forming the emissive layer with a mixture of a rare earth phosphor, a blue-green phosphor, and a deep red phosphor, and forming a non-emissive layer, the color rendering property is improved and ultraviolet rays are cut. Both effects can be obtained, and a fluorescent lamp suitable as a light source for exhibiting fish, shellfish, meat, etc. can be provided.

Claims (5)

[Claims] (1) In a glass bulb in which a light-emitting layer is formed on the inner surface, a non-light-emitting layer is formed between the glass bulb and the light-emitting layer and has a translucent property and has an ultraviolet absorbing effect, and the light-emitting layer is formed into a narrow-band light emitting type. It is composed of a mixed member of a phosphor, a blue-green phosphor and a deep red phosphor that are excited by visible light, and the ratio of each of the blue-green phosphor and the deep red phosphor to the mixed member is A fluorescent lamp characterized in that the concentration is set at 5 to 30% by weight. (2) The fluorescent lamp according to claim 1, wherein the non-emissive layer is mainly composed of titanium oxide. (3) Narrow band emitting type phosphor is 450, 540, 610n
Claim 1, characterized in that it is composed of a plurality of phosphors having emission peaks in three wavelength regions near m.
Fluorescent lamps as described in Section. (4) The blue-green phosphor is composed of a phosphor that has an emission peak near 490 nm and is excited even in the blue region. Fluorescent lamp. (5) The fluorescent light according to claim 1, characterized in that the deep red fluorescent material has an emission peak near 660 nm and is composed of a fluorescent material that is also excited in the blue region. lamp.